Wireless Local Area Network (WLAN) interworking and integration is currently supported at the Core Network (CN) level, including both seamless and non-seamless mobility to WLAN. However, as operator controlled WLAN deployments become more common and WLAN usage increases, Radio Access Network (RAN) level enhancements for WLAN interworking can improve user experience, provide more operator control and better access network utilization to reduce Operational Expenditure (OPEX).
RAN level 3rd Generation Partnership Project (3GPP)/WLAN interworking was proposed by Intel™ to 3GPP Technical Specification Groups (TSG) RA #58 with wide support of other companies including several operators as well as user equipment (UE) and network vendors (see RP-122038, entitled “New Study Item Proposal on WLAN/3GPP Radio Interworking”).
In the Long Term Evolution (LTE) and Universal Mobile Telecommunications System (UMTS) standards, CN based approaches have been identified to balance load. These approaches often involve intra-Radio Access Technology (RAT) or inter-RAT handovers. Alternatively, a network may simply limit the access of certain user equipment (UE) to network resources, i.e. utilizing access class barring (ACB).
The 3rd Generation Partnership Project Technical Specification (3GPP TS) 24.312 describes an Access Network Discovery and Selection Function (ANDSF), located within the CN. The ANDSF is intended to provide an Inter-System Routing Policy (ISRP) to the UE for offloading. The ISRP may include parameters such as cellular network topology based location (serving network, location area, cell ID), geo-location date and time of day, Access Point Name (APN), IP address type, IP address and port number.
While these 3GPP CN based solutions enable UEs to offload data connections to non-3GPP access network; the UE controls whether to trigger usage of these offloading methods. As the UE is not made aware of the load situation within a 3GPP network, it cannot know when it would be beneficial from the network point of view to trigger offloading to non-3GPP access networks even if one would be available nearby.
Therefore, there is a desire for improved measures for use in access network selection.